/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.jasper.tagplugins.jstl.core;

import org.apache.jasper.compiler.tagplugin.TagPlugin;
import org.apache.jasper.compiler.tagplugin.TagPluginContext;
import org.apache.jasper.tagplugins.jstl.Util;

public class Url implements TagPlugin {

	public void doTag(TagPluginContext ctxt) {

		// flags
		boolean hasVar, hasContext, hasScope;

		// init flags
		hasVar = ctxt.isAttributeSpecified("var");
		hasContext = ctxt.isAttributeSpecified("context");
		hasScope = ctxt.isAttributeSpecified("scope");

		// define name of the temp variables
		String valueName = ctxt.getTemporaryVariableName();
		String contextName = ctxt.getTemporaryVariableName();
		String baseUrlName = ctxt.getTemporaryVariableName();
		String resultName = ctxt.getTemporaryVariableName();
		String responseName = ctxt.getTemporaryVariableName();

		// get the scope
		String strScope = "page";
		if (hasScope) {
			strScope = ctxt.getConstantAttribute("scope");
		}
		int iScope = Util.getScope(strScope);

		// get the value
		ctxt.generateJavaSource("String " + valueName + " = ");
		ctxt.generateAttribute("value");
		ctxt.generateJavaSource(";");

		// get the context
		ctxt.generateJavaSource("String " + contextName + " = null;");
		if (hasContext) {
			ctxt.generateJavaSource(contextName + " = ");
			ctxt.generateAttribute("context");
			ctxt.generateJavaSource(";");
		}

		// get the raw url
		ctxt.generateJavaSource("String " + baseUrlName + " = "
				+ "org.apache.jasper.tagplugins.jstl.Util.resolveUrl("
				+ valueName + ", " + contextName + ", pageContext);");
		ctxt.generateJavaSource("pageContext.setAttribute"
				+ "(\"url_without_param\", " + baseUrlName + ");");

		// add params
		ctxt.generateBody();

		ctxt.generateJavaSource("String " + resultName + " = "
				+ "(String)pageContext.getAttribute(\"url_without_param\");");
		ctxt
				.generateJavaSource("pageContext.removeAttribute(\"url_without_param\");");

		// if the url is relative, encode it
		ctxt
				.generateJavaSource("if(!org.apache.jasper.tagplugins.jstl.Util.isAbsoluteUrl("
						+ resultName + ")){");
		ctxt.generateJavaSource("    HttpServletResponse " + responseName
				+ " = " + "((HttpServletResponse) pageContext.getResponse());");
		ctxt.generateJavaSource("    " + resultName + " = " + responseName
				+ ".encodeURL(" + resultName + ");");
		ctxt.generateJavaSource("}");

		// if "var" is specified, the url string store in the attribute var
		// defines
		if (hasVar) {
			String strVar = ctxt.getConstantAttribute("var");
			ctxt.generateJavaSource("pageContext.setAttribute" + "(\"" + strVar
					+ "\", " + resultName + ", " + iScope + ");");

			// if var is not specified, just print out the url string
		} else {
			ctxt.generateJavaSource("try{");
			ctxt.generateJavaSource("    pageContext.getOut().print("
					+ resultName + ");");
			ctxt.generateJavaSource("}catch(java.io.IOException ex){");
			ctxt
					.generateJavaSource("    throw new JspTagException(ex.toString(), ex);");
			ctxt.generateJavaSource("}");
		}
	}

}
